/*(C) 2007-2012 Alibaba Group Holding Limited.	 *This program is free software; you can redistribute it and/or modify	*it under the terms of the GNU General Public License version 2 as	* published by the Free Software Foundation.	* Authors:	*   junyu <junyu@taobao.com> , shenxun <shenxun@taobao.com>,	*   linxuan <linxuan@taobao.com> ,qihao <qihao@taobao.com> 	*/	///*
// * @(#)NavigableSet.java	1.5 06/05/10
// *
// * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
// * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
// */
//
//package com.taobao.tddl.common.util;
//
//import java.util.Iterator;
//import java.util.SortedSet;
//
///**
// * A {@link SortedSet} extended with navigation methods reporting
// * closest matches for given search targets. Methods {@code lower},
// * {@code floor}, {@code ceiling}, and {@code higher} return elements
// * respectively less than, less than or equal, greater than or equal,
// * and greater than a given element, returning {@code null} if there
// * is no such element.  A {@code NavigableSet} may be accessed and
// * traversed in either ascending or descending order.  The {@code
// * descendingSet} method returns a view of the set with the senses of
// * all relational and directional methods inverted. The performance of
// * ascending operations and views is likely to be faster than that of
// * descending ones.  This interface additionally defines methods
// * {@code pollFirst} and {@code pollLast} that return and remove the
// * lowest and highest element, if one exists, else returning {@code
// * null}.  Methods {@code subSet}, {@code headSet},
// * and {@code tailSet} differ from the like-named {@code
// * SortedSet} methods in accepting additional arguments describing
// * whether lower and upper bounds are inclusive versus exclusive.
// * Subsets of any {@code NavigableSet} must implement the {@code
// * NavigableSet} interface.
// *
// * <p> The return values of navigation methods may be ambiguous in
// * implementations that permit {@code null} elements. However, even
// * in this case the result can be disambiguated by checking
// * {@code contains(null)}. To avoid such issues, implementations of
// * this interface are encouraged to <em>not</em> permit insertion of
// * {@code null} elements. (Note that sorted sets of {@link
// * Comparable} elements intrinsically do not permit {@code null}.)
// *
// * <p>Methods
// * {@link #subSet(Object, Object) subSet(E, E)},
// * {@link #headSet(Object) headSet(E)}, and
// * {@link #tailSet(Object) tailSet(E)}
// * are specified to return {@code SortedSet} to allow existing
// * implementations of {@code SortedSet} to be compatibly retrofitted to
// * implement {@code NavigableSet}, but extensions and implementations
// * of this interface are encouraged to override these methods to return
// * {@code NavigableSet}.
// *
// * <p>This interface is a member of the
// * <a href="{@docRoot}/../technotes/guides/collections/index.html">
// * Java Collections Framework</a>.
// *
// * @author Doug Lea
// * @author Josh Bloch
// * @param <E> the type of elements maintained by this set
// * @since 1.6
// */
//public interface NavigableSet<E> extends SortedSet<E> {
//    /**
//     * Returns the greatest element in this set strictly less than the
//     * given element, or {@code null} if there is no such element.
//     *
//     * @param e the value to match
//     * @return the greatest element less than {@code e},
//     *         or {@code null} if there is no such element
//     * @throws ClassCastException if the specified element cannot be
//     *         compared with the elements currently in the set
//     * @throws NullPointerException if the specified element is null
//     *         and this set does not permit null elements
//     */
//    E lower(E e);
//
//    /**
//     * Returns the greatest element in this set less than or equal to
//     * the given element, or {@code null} if there is no such element.
//     *
//     * @param e the value to match
//     * @return the greatest element less than or equal to {@code e},
//     *         or {@code null} if there is no such element
//     * @throws ClassCastException if the specified element cannot be
//     *         compared with the elements currently in the set
//     * @throws NullPointerException if the specified element is null
//     *         and this set does not permit null elements
//     */
//    E floor(E e);
//
//    /**
//     * Returns the least element in this set greater than or equal to
//     * the given element, or {@code null} if there is no such element.
//     *
//     * @param e the value to match
//     * @return the least element greater than or equal to {@code e},
//     *         or {@code null} if there is no such element
//     * @throws ClassCastException if the specified element cannot be
//     *         compared with the elements currently in the set
//     * @throws NullPointerException if the specified element is null
//     *         and this set does not permit null elements
//     */
//    E ceiling(E e);
//
//    /**
//     * Returns the least element in this set strictly greater than the
//     * given element, or {@code null} if there is no such element.
//     *
//     * @param e the value to match
//     * @return the least element greater than {@code e},
//     *         or {@code null} if there is no such element
//     * @throws ClassCastException if the specified element cannot be
//     *         compared with the elements currently in the set
//     * @throws NullPointerException if the specified element is null
//     *         and this set does not permit null elements
//     */
//    E higher(E e);
//
//    /**
//     * Retrieves and removes the first (lowest) element,
//     * or returns {@code null} if this set is empty.
//     *
//     * @return the first element, or {@code null} if this set is empty
//     */
//    E pollFirst();
//
//    /**
//     * Retrieves and removes the last (highest) element,
//     * or returns {@code null} if this set is empty.
//     *
//     * @return the last element, or {@code null} if this set is empty
//     */
//    E pollLast();
//
//    /**
//     * Returns an iterator over the elements in this set, in ascending order.
//     *
//     * @return an iterator over the elements in this set, in ascending order
//     */
//    Iterator<E> iterator();
//
//    /**
//     * Returns a reverse order view of the elements contained in this set.
//     * The descending set is backed by this set, so changes to the set are
//     * reflected in the descending set, and vice-versa.  If either set is
//     * modified while an iteration over either set is in progress (except
//     * through the iterator's own {@code remove} operation), the results of
//     * the iteration are undefined.
//     *
//     * <p>The returned set has an ordering equivalent to
//     * <tt>{@link Collections#reverseOrder(Comparator) Collections.reverseOrder}(comparator())</tt>.
//     * The expression {@code s.descendingSet().descendingSet()} returns a
//     * view of {@code s} essentially equivalent to {@code s}.
//     *
//     * @return a reverse order view of this set
//     */
//    NavigableSet<E> descendingSet();
//
//    /**
//     * Returns an iterator over the elements in this set, in descending order.
//     * Equivalent in effect to {@code descendingSet().iterator()}.
//     *
//     * @return an iterator over the elements in this set, in descending order
//     */
//    Iterator<E> descendingIterator();
//
//    /**
//     * Returns a view of the portion of this set whose elements range from
//     * {@code fromElement} to {@code toElement}.  If {@code fromElement} and
//     * {@code toElement} are equal, the returned set is empty unless {@code
//     * fromExclusive} and {@code toExclusive} are both true.  The returned set
//     * is backed by this set, so changes in the returned set are reflected in
//     * this set, and vice-versa.  The returned set supports all optional set
//     * operations that this set supports.
//     *
//     * <p>The returned set will throw an {@code IllegalArgumentException}
//     * on an attempt to insert an element outside its range.
//     *
//     * @param fromElement low endpoint of the returned set
//     * @param fromInclusive {@code true} if the low endpoint
//     *        is to be included in the returned view
//     * @param toElement high endpoint of the returned set
//     * @param toInclusive {@code true} if the high endpoint
//     *        is to be included in the returned view
//     * @return a view of the portion of this set whose elements range from
//     *         {@code fromElement}, inclusive, to {@code toElement}, exclusive
//     * @throws ClassCastException if {@code fromElement} and
//     *         {@code toElement} cannot be compared to one another using this
//     *         set's comparator (or, if the set has no comparator, using
//     *         natural ordering).  Implementations may, but are not required
//     *         to, throw this exception if {@code fromElement} or
//     *         {@code toElement} cannot be compared to elements currently in
//     *         the set.
//     * @throws NullPointerException if {@code fromElement} or
//     *         {@code toElement} is null and this set does
//     *         not permit null elements
//     * @throws IllegalArgumentException if {@code fromElement} is
//     *         greater than {@code toElement}; or if this set itself
//     *         has a restricted range, and {@code fromElement} or
//     *         {@code toElement} lies outside the bounds of the range.
//     */
//    NavigableSet<E> subSet(E fromElement, boolean fromInclusive,
//                           E toElement,   boolean toInclusive);
//
//    /**
//     * Returns a view of the portion of this set whose elements are less than
//     * (or equal to, if {@code inclusive} is true) {@code toElement}.  The
//     * returned set is backed by this set, so changes in the returned set are
//     * reflected in this set, and vice-versa.  The returned set supports all
//     * optional set operations that this set supports.
//     *
//     * <p>The returned set will throw an {@code IllegalArgumentException}
//     * on an attempt to insert an element outside its range.
//     *
//     * @param toElement high endpoint of the returned set
//     * @param inclusive {@code true} if the high endpoint
//     *        is to be included in the returned view
//     * @return a view of the portion of this set whose elements are less than
//     *         (or equal to, if {@code inclusive} is true) {@code toElement}
//     * @throws ClassCastException if {@code toElement} is not compatible
//     *         with this set's comparator (or, if the set has no comparator,
//     *         if {@code toElement} does not implement {@link Comparable}).
//     *         Implementations may, but are not required to, throw this
//     *         exception if {@code toElement} cannot be compared to elements
//     *         currently in the set.
//     * @throws NullPointerException if {@code toElement} is null and
//     *         this set does not permit null elements
//     * @throws IllegalArgumentException if this set itself has a
//     *         restricted range, and {@code toElement} lies outside the
//     *         bounds of the range
//     */
//    NavigableSet<E> headSet(E toElement, boolean inclusive);
//
//    /**
//     * Returns a view of the portion of this set whose elements are greater
//     * than (or equal to, if {@code inclusive} is true) {@code fromElement}.
//     * The returned set is backed by this set, so changes in the returned set
//     * are reflected in this set, and vice-versa.  The returned set supports
//     * all optional set operations that this set supports.
//     *
//     * <p>The returned set will throw an {@code IllegalArgumentException}
//     * on an attempt to insert an element outside its range.
//     *
//     * @param fromElement low endpoint of the returned set
//     * @param inclusive {@code true} if the low endpoint
//     *        is to be included in the returned view
//     * @return a view of the portion of this set whose elements are greater
//     *         than or equal to {@code fromElement}
//     * @throws ClassCastException if {@code fromElement} is not compatible
//     *         with this set's comparator (or, if the set has no comparator,
//     *         if {@code fromElement} does not implement {@link Comparable}).
//     *         Implementations may, but are not required to, throw this
//     *         exception if {@code fromElement} cannot be compared to elements
//     *         currently in the set.
//     * @throws NullPointerException if {@code fromElement} is null
//     *         and this set does not permit null elements
//     * @throws IllegalArgumentException if this set itself has a
//     *         restricted range, and {@code fromElement} lies outside the
//     *         bounds of the range
//     */
//    NavigableSet<E> tailSet(E fromElement, boolean inclusive);
//
//    /**
//     * {@inheritDoc}
//     *
//     * <p>Equivalent to {@code subSet(fromElement, true, toElement, false)}.
//     *
//     * @throws ClassCastException       {@inheritDoc}
//     * @throws NullPointerException     {@inheritDoc}
//     * @throws IllegalArgumentException {@inheritDoc}
//     */
//    SortedSet<E> subSet(E fromElement, E toElement);
//
//    /**
//     * {@inheritDoc}
//     *
//     * <p>Equivalent to {@code headSet(toElement, false)}.
//     *
//     * @throws ClassCastException       {@inheritDoc}
//     * @throws NullPointerException     {@inheritDoc}
//     * @throws IllegalArgumentException {@inheritDoc}
//na     */
//    SortedSet<E> headSet(E toElement);
//
//    /**
//     * {@inheritDoc}
//     *
//     * <p>Equivalent to {@code tailSet(fromElement, true)}.
//     *
//     * @throws ClassCastException       {@inheritDoc}
//     * @throws NullPointerException     {@inheritDoc}
//     * @throws IllegalArgumentException {@inheritDoc}
//     */
//    SortedSet<E> tailSet(E fromElement);
//}
